The present invention relates in general to needle holders for use in surgery, and in particular, to endoscopic needle holders with suture grasping abilities.
In endoscopic surgery, one or more needle holders are used with specialized surgical needles (wherein the needle is swaged or attached to the suture), to apply a suture to a surgical site within a patients body. Needle holders can be used in conjunction with other surgical devices such as knot deploying devices, knot tying devices, and needle driving devices. The needle holder is introduced through a cannula and is manipulated by the operator. The needle holder is generally comprised of a handle, an elongated shaft and a pair of grasping jaws. One or more jaws are moveable and are actuated by manipulation of handle controls. The jaws grasp the surgical needle and are used to manipulate the needle to produce endoscopic sutures.
Needle holders can hold or grasp various sized surgical needles at any position, proximal or distal, within the grasper jaws. For a given force input at the handle, the force exerted upon the needle by the jaw components varies as a function of the distance of the needle from the moveable jaw pivot point, and the needle diameter. The more distal the needle grasping location, the higher the forces on the needle, the bearings, and the clamping jaw. The larger the needle diameter, the higher the forces on the needle and jaw components. Thus, grasping a large diameter needle within the distal portion of the jaws could damage both the needle and instrument, or reduce the life of the instrument. It would therefore be desirable to apply a force limiting device within the needle holder to limit the amount of force applied by the grasper jaws, regardless of the position of the closure trigger, or needle diameter. Such a device is described in U.S. Pat. No. 5,413, 583 by Udo Wohlers, herein incorporated as a reference.
With the addition of a force limiting device to the needle holder, endoscopic suturing became easier and more readily accepted. However, there were still difficulties in grasping and manipulating needles in the laparoscopic environment. Control of the needle is important for endoscopic suture placement. Three distinct types of needle motion within the grasper jaws are possible, these are: 1.) needle rotation, wherein the needle point and swage rotate in unison about the grasping point; 2.) needle toggling, wherein the point and swage move, in the same plane, and in opposite directions about the grasping point; 3.) needle slippage, wherein the needle slides within the jaws and the grasping point moves closer to the tip of the needle. Additionally, it is of great value to position the needle into the needle holder in a generally transverse orientation that is suitable for placing a stitch. As described by Measamer et al. in U.S. Pat. No. 5,601,575 herein incorporated as a reference, the use of a three point needle system grasping system in conjunction with a curved needle addressed these issues. Additionally, the three point grasper design described causes the needle to "right" or snap into a position wherein the needle curvature is vertical and perpendicular to the longitudinal axis of the instrument. The "righted" needle position greatly facilitates the needle placement, but is not adequate to grasp suture.
With the breakthrough "righting" needle feature, endoscopic suturing reached a new level. However, there are still difficulties with endoscopic suturing as the needle grasper can only grasp the needle, and is not adequate to grasp suture. In endoscopic surgery, the space available within the patient is limited. Additionally, the surgical site is crowded with surgical devices such as trocar cannulas, dissectors, graspers, knot tying devices, and the like. The restricted space, when combined with a long suture, and the limited range of motion available with endoscopic access ports, can make it very difficult to tighten a stitch or knot. Thus it would be advantageous, when tying a knot or tensioning a suture loop, to grasp the suture close to the stitch or knot, rather than at the needle in connection with use of an instrument that grasps a needle.